The present invention relates to a display system for displaying images representing real-time data simultaneously with images representing non-real-time data.
Systems for displaying images representing real-time data have a long history. For example, systems have long existed for displaying a waveform image representing real-time physiological data such as electrocardiogram (ECG) data. More recently, systems have been developed for simultaneously displaying multiple images representing respective real-time data. For example, current ECG systems can simultaneously display all 12 waveforms of a full 12 lead ECG. U.S. Pat. No. 6,104,948, issued Aug. 15, 2000 to Bogart et al., discloses a system for receiving a plurality of physiological real-time data from different sources, such as ECG, electroencephalogram (EEG), skin conductance information, oculometer derived look-point data, and skin temperature. The system also receives other real-time data such as cardiac cine-loop video. The system then simultaneously and synchronously displays a composite image containing the respective images representing all of the received real-time data. The composite image may be recorded utilizing a scan converter on a video tape recorder for future study.
Systems for simultaneously displaying images representing respective non-real-time data also exist. For example, computer windowing operating systems, such as UNIX X-windows, Apple Macintosh and Microsoft Windows permit programs to be written for displaying multiple images representing respective non-real-time data. For example, U.S. Pat. No. 5,956,013, issued Sep. 21, 1999 to Raj et al. discloses a Microsoft Windows based system for receiving prerecorded ECG data from, e.g. a Holter heart monitor, and displaying a first image of a waveform representing several seconds of ECG data, and simultaneously displaying a second image of a selected number (e.g. one to five) of heartbeat waveforms atop each other aligned on their R waves.
Further systems exist for simultaneously displaying images representing real-time data and images representing non-real-time data. For example, computer systems operating under the control of the above mentioned windowing operating systems have been designed to include a real-time data collection device, and images representing the gathered real-time data have been displayed simultaneously with images representing non-real-time data. U.S. Pat. No. 4,845,653, issued Jul. 4, 1989 to Conrad et al. discloses a system in which a plurality of two parameter data fields are simultaneously displayed representing respective views of the same multi-parameter data. This data may be displayed in real-time as it is received. A user may define an outline enclosing an area in one of the data fields, and the data points corresponding to those within that area are highlighted in the other data fields. Further non-real-time information, derived from the enclosed data points, may also be displayed.
One skilled in the art will understand that the computer windowing operating systems, described above, make it relatively simple to design and implement a program to simultaneously display real-time and non-real-time data. Consequently, many programs have been written to perform a wide variety of very desirable tasks for these operating systems. One skilled in the art will also understand that such operating systems are not reliable and will often require restarting, resetting or rebooting, particularly when executing a program or multiple programs including multiple tasks or threads. However, it is always desirable for systems to operate with high reliability. In some applications, such as medical monitoring equipment, it is imperative that the system operate with the highest possible reliability. For example, for an ECG monitor, the display of the waveform images representing the ECG data must never be interrupted, and further must proceed with a minimum latency time between receipt of the real-time ECG data and the display of that data.
One skilled in the art will understand that display of non-real-time data simultaneously with display of the real-time (e.g. ECG) data would be useful. For example, a doctor analyzing a patient""s real-time ECG display might desire to simultaneously display textual lab results for the patient, or an image of an X-ray, or data from the patient""s chart, or even information from a pharmaceutical company""s web site. The skilled practitioner will also appreciate the advantages provided by using a windowing operating system as the basis for such a system, such as familiarity of use, ease of programming and the availability of a wide variety of programs. Finally, the skilled practitioner will appreciate that, while display of non-real-time information is important and desirable, a malfunction in the non-real-time data display program (such as must be expected when using such windowing operating systems) must not be allowed to interrupt the display of the real-time ECG data under any circumstances. Thus, a system which permits simultaneous display of real-time and non-real-time data using existing windowing operating systems, but which does not permit malfunction in the display of the non-real-time data to interrupt the display of the real-time data is desirable.
In accordance with principles of the present invention, a method and apparatus for concurrently displaying respective images representing real-time data and non-real-time data operates by first receiving non-real-time data and receiving real-time data. A windowing operating system is executed for controlling the operation of an application program which is responsive to the non-real-time data, for conditioning a display device to display respective images representing the non-real-time data. A real-time display process is executed concurrently with, but independently from, the windowing operating system, for conditioning the display device to display respective images representing the real-time data concurrently with the display of the non-real-time data.